Bag stacking mechanism



Oct. ;1, 1963 F. E. SIMPSON ETAL 3,105,422

' BAG STACKING MECHANISM on inai Filed May 22, 1959 5 Sheets-Sheet 1 20 1 -1 E 1 782 {LL- 780 m I INVENTORS N N FRANK E. SIMPSON JOHN D. HOFFMAN ATTORNEY 1, 1963 F. E. SIMPSON ETAL 3,105,422

BAG STACKIING MECHANISM 5 Sheets-Sheet 3 Original Filed May 22, 1959 BY M 44 ATTORNEY 06b1, 963 F. E. SIMPSON El'AL' 3,105,422

BAG STACKING MECHANISM 5 Sheets-Sheet 4 Original Filed May 22, 1959 INVENTORS FRANK E. SIMPSON JOHN D. HOFFMAN ATTORNEY 5 F. E. SIMPSON ETAL 3,105,422

BAG STACKING MECHANISM Original Filed May 22, 1959 5 Sheets-Sheet 5 INVENTORS FRANK E. SIMPSON JOHN D. HOFFMAN VCL ATTORNEY United States Patent 3 Claims. (Cl. 93-93 This invention relates to bag making machinery, and more particularly to accumulator mechanisms for collecting and discharging uniform stacks of finished bags.

An object of the present invention is to provide an improved mechanism for piling bags supplied successively' thereto into uniform stacks each consisting of a predetermined number of bags.

Another object is to provide a bag stacking mechanism particularly suited for, but not necessarily limi ed to, the stacking of bags made of flimsy sheet material.

Another object is to provide a bag stacker capable of handling bags made of sheet material having little body or inherent stifiness, which stacker is adapted for incorporation into an automatic bag making machine as one of the operative components thereof.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings in which:

FIG. 1 is an enlarged fragmentary plan of the discharge end of a bag-making machine having as one of its operative components the improved mechanism of the present invention for collecting the finished bags into groups and for arraying the groups into orderly piles, each containing a predetermined number of bags.

FIG. 2 is an enlarged, fragmentary, partly broken away section along lines 22 of FIG. 1.

FIG. 3 is a further enlarged section along lines 33 of FIG. 1 through the drum whereby the bags are collected in groups.

FIG. 4 is a fragmentary elevation viewed as indicated by the lines 44 of FIG. 1 to show some of the drive arrangement for the collecting, stacking, and discharge mechanisms.

FIG. 5 is an enlarged fragmentary section along lines 55 of FIG. 1 showing a cam arrangement constituting an operative part of the collecting drum of FIG. 3.

FIGS. 6-10, inclusive, are schematic operational views showing successive steps in the operation of the collecting drum of FIG. 3.

The accumulator mechanism of the present invention is disclosed in our prior application, Serial No. 815,159,

filed May 22, 1959, of which this application constitutes a division.

The bag-making machine 20 partially shown in FIG. 1 of the aforesaid prior application includes a mechanism for severing lengths of stock from a continuous strip of tubular bag stock and for transferring the successive bag lengths to a sealing drum 24 (FIGS. 1 and 2) that transversely seals each bag length at or adjacent one end thereof, thus forming each bag length of stock into a complete bag of rectangular shape.

Inasmuch as the present invention is not concerned with the manner in which the parent strip of bag stock is prepared, or the manner in which the stock is severed and sealed, it will suffice for the purposes of the present disclosure to state that the parent strip is of flattened tubular form and is continuously advanced at a uniform rate by feed rollers and that the parent stock fromwhich the completed bags are made can be of any heat scalable sheet material such as polyethylene- The present invention comprises an accumulator mechanism for completed bags and includes -a stacking 3,105,422 Patented Oct. 1, 1963 mechanism 26 (FIGS. 1-4) that stacks the completed bags in uniform piles, each consisting of a predetermined number of bags, upon an intermittently advanced discharge conveyor 28 whereby the segregated piles are discharged from the bag-making machine 20.

Immediately above the sealing drum 24 that seals the ends of the bags is mounted a transfer mechanism 370 (FIGS. 1 and 2) for transferring the successive completed bags to the stacking mechanism 26 of the present invent-ion. This transfer mechanism 370 comprises a series of parallel belts 372 trained around a vacuum drum (not shown), around a smaller drum 374, and around a series of rollers or wheels 376, one of which is shown in FIGS. 2 and 3. Each of the rollers 376 is rotatable upon a pin 37S and each pin is clamped within the corresponding end of a link 330. The other ends of the several links 389 are clamped on a transversely extending rod 382 by means of a bolt 384, one of which is associated with each link 386. Each bolt 384 extends through one side of the associated link 38!} and across a slot 386 separating the two sides of the link and is threaded into the opposite side of the link so that when the bolt 384 is tightened the link is clamped upon the rod 382. This arrangement permits individually adjusting the several rollers 376 so that the tension of the several belts 372 can be regulated individually.

The rollers 375 (FIG. 2) and the vacuum drum are so positioned that their respective circumferential surfaces are closely adjacent the periphery of the sealing drum 24. The rollers 376 and the vacuum drum are spaced apart, i.e., they are angularly separated around the surface of the sealing drum 24 a sufiicient distance for the belts 372 to make contact with the surface of the drum 24 throughout an arc whose angular extent is on the order of from 60 to The transfer mechanism 370 includes another series of belts 4% which are operably mounted immediately above the upper runs of the belts 372. Advantageously, each of the belts 4% is in the form of a spiral spring and the belts 490 correspond in number to that of the belts 372, being so disposed that one of the belts 400 lies immediately above one of the belts 372 with the lower run of the belt 4% parallel to and closely adjacent the upper run ofthe associated belt 372. The belts 4% are trained around parallel, longitudinally spaced, grooved rollers 4S4, which are suitably journalled in and extend between the frame sides 32 and 34. Each successive bag handled by the transfer mechanism 370 is advanced toward the left as viewed in FIGS. 1 and 2. Each bag is grasped between the upper runs of the belts 372 and the lower runs of the belts 40%.

The roller 4% (FIG. 3) of the upper series of belts 406 is so positioned that the belts 409 are enabled to hold the successive bag lengths against the upper surfaces of the upper'runs of the belts 372 until they have passed slightly beyond the. vertical plane that includes the axis of the drum 374. From this position the successive bags are carried obliquely downward and forward to the lower portion of the circumference of a collecting drum 41% (FIGS. 1-4) which is positively rotated in timed relationship with the other operating components of the machine 2%) by means of an idler gear 412 (FIGS. 2 and 3) freely journalled on the frame side 32 and enmeshed with the large gear of the transverse sealing drum 24 and with a gear 414 mounted at one end 415 of the collecting drum 410 (FIG. 3). Another idler gear 416 freely journalled upon an extension 418 of the frame side 32 is enmeshed with the gear 414 of the collecting drum 410 and with a gear 420 rigid with the roller 404, thus providing means for positively driving the upper series of belts 4% of the transfer mechanism 370. 'The gear 426 is likewise enmeshed with a gear 422 3 (FIG. 3) rigid with the drum 374 about which the lower series of [belts 372 of the transfer mechanism 379 are trained. v

The gear 422 of the drum 374 drives still another series of belts 426 which extend obliquely downward and forward from the drum 374 so that the upper runs of the belts 426 engage the circumference of the collecting drum 410 throughout arcs of considerable angular extent, as best shown in FIG. 3. The belts 426 are advantageously of the spiral spring type so that their upper runs are held firmly and yet yieldably in engagement with the drum 410 throughout the full extent of these arcs. The belts 426 are trained around a grooved idler roller 428 which is carried by a shaft 43% extending between frame extensions 432 and 434.

Thus, it may be seen that the belts 426 carry the bags successively from the discharge end of the transfer mechanism 370 downward and forward so as to press them against the circumference of the rotating collecting drum 410. To assist the belts 426 in so directing the bags from the transfer mechanism 370 an auxiliary series of relatively short .belts 436 are trained around the grooved roller 464 (FIG. 3) and around a smaller idler roller 438 which preferably is similarly grooved and is rotatably supported by and extends between extensions 432 and 434 of the frame sides 32 and 34, respectively. The lower runs of the belts 436 are inclined downward and forward from the roller 404 so that as a bag leaves the belts 372 and 400 it is deflected downward and thus caused to lie upon the upper runs of the belts 426 which guide the leadnig end of each succeeding bag into engagement with the circumference of the drum 410 to lie flat thereagainst and to advance therewith as the drum 410 turns.

The collecting drum 410 (FIGS. 1 and 2) constitutes the first operating component of the stacking mechanism 26. It is provided with an opening 440 (FIG. 3)-in its circumferential wall extending the full length thereof, through which stationary and movable gripping jaws 442 and 444, respectively, are exposed. The stationary jaw 442 comprises a backing bar 446 within and extending the full length of the drum- 410 adjacent the edge of the opening 440 that trails during rotation of the drum. A plurality of spaced-apart fingers 448 project forward from the backing bar 446, i.e., project from the backing bar toward the edge of the opening 440 that leads during rotation of the drum.

'l he movable jaw 444 likewise comprises a backing bar 450 within the drum 410. The backing bar 450, however, is of slightly greater length than the drum and is provided with a plurality of fingers 452 projecting therefrom in the opposite direction from that in which the drum 410 rotates. The backing bar 450 of the movable jaw 444 is carried by two arms 460 (FIG. 3) and 466a (FIG. 5 respectively, each of which is pivotally mounted upon one of the heads 415 of the drum 410 by a pivot pin 462. The arm 460a (FIG. 5) is mounted on the outer surface of its associated drum head 415 and is formed with a lateral extension on the outer end of which a cam follower roller 466 is rotatably mounted. This roller 466 is engaged within a cam groove 468 of a face cam 470 (FIGS. 1 and 5) which is afiixed as by a key 472 to the shaft 474 which bears the weight of the collecting drum 410. It should be noted, however, that the drum 410 is free to rotate about the shaft 474.

Throughout the major portion of its angular extent the cam groove 468 is at constant radial distance from the axis of'the shaft 474. It is provided with a rise 476,

' however, i.e., a short section at somewhat greater radial distance from the axis of the shaft 474, and throughout the period that the cam follower roller 466 is within the rise portion 476 of the groove 468 the movable jaw 444 is held in its open position as illustrated in FIGS. 2, 3, 5, and 10. However, throughout the time that the cam follower roller 466 is within the portion 478 of the groove 4 468 of lesser radius the movable jaw 444 is held with its fingers 452 in clamping relation with the fingers 448 of the fixed jaw 442 as illustrated in FIGS. 7-9.

The shaft 474 is suitably journalled in the frame extensions 432 and 434 and is provided with means for turning it a few degrees to rotate the disc cam 470 between two alternative operating positions. In the first position of the disc cam 470 the movable jaw 444 of the collec ing drum 410 is caused to open in time for the leading edge of a bag being advanced by the belts 426 toward the drum 416 to enter between the fingers 452 of the movable jaw and the fingers 448 of the stationary jaw 442, it being understood that when the movable jaw is in its open position the fingers 452 of the movable jaw project radially outward slightly beyond the belts 426, i.e., to positions below the belts 426 and, consequently, well below the leading edge of the bag that is pressed against the circumference of the drum by the upper surface of the belts 426, as is best understood by reference to FIG. 3.

Just before the movable jaw 444 is rotated beyond the place where the belts 426 become straight and project tangentially from the circumference of the drum 410 the cam follower roller 466 passes out of the rise 476, thus closing the movable jaw 444 and causing the bag to be firmly gripped between the movable and the fixed jaws 444 and 442, respectively, before the leading edge of the bag is permitted to depart from the circumference of the drum 410. Therefore, as the drum 4143 continues to rotate, it carries the bag on around with it and when the jaw 444 again approaches the place of tangency of the belts 426 with the circumference of the drum, the jaw 444 opens, permitting the next succeeding bag also to enter between the fingers 452 of the movable jaw and the fingers 443 of the fixed jaw so that the second bag likewise is clamped between the two jaws before it is given an apportunity to depart from the circular orbit in which it .is then being carried by the drum.

This operation of the collecting drum 410 to collect bags with their leading edges gripped between the movable and fixed jaws 444 and 442, respectively, is repeated a predetermined number of times so as to collect the desired number of bags before the group of bags is released for passage on beyond the collecting drum 4%. In the exemplary machine 20 illustrated, the collecting operation is twice repeated, i.e., it occurs three times so as to collect three successive bags and to carry them around the drum. As the jaw 444 approaches the belts 426 for the fourth time, however, the disc ,cam 470' is rotated a few degrees in the direction of drum rotation so that the action of the cam follower roller 466 to open the jaw 444 is deferred until it is too late for the leading edge of the fourth bag to enter between the movable and fixed jaws 444 and 442, respectively. Moreover, the action of the cam follower 466 in closing the movable jaw 444 is likewise deferred until after the jaws 442 and444 have passed beyond the place where the belts 426 depart from the circumference of the drum 410, thus permitting the four collected bags to travel in a straight tangential line from the circcumference of the drum 410, in which movement they are guided by the belts 426 until they reach the idler roller 428.

The mechanism for thus shifting the disc cam 476 be tween the two described operating positions comprises a crank arm 490 (FIGS. 1 and 3) fixed to the end of the shaft 474 opposite that to which the disc cam 47% is attached. A cam follower roller 492 (FIG. 3) is rotatably mounted upon the crank arm 4% for free rotation about an axis spaced radially from the axis of the shaft 474. The roller 492 is engaged within a cam groove 494 (FIG. 3) of a disc cam 496 (FIGS. 1 and 4) which is secured to a stub shaft 498 (FIG. 4) suitably journalled upon and projecting laterally outward from the frame extension 432. The stubshaft 493 likewise carries a sprocket 500 which is driven by means of a chain 592 from a sprocket 504 rigid with the shaft 506 of the transverse sealing drum 24, it being understood that the shaft 506 is rigidly secured to the drum 24, and that both the drum 24 and shaft 566 are rotated by the driving motor (not shown) of the machine 26.

The parts are so proportioned that the disc earn 496 makes one complete revolution for each full revolution of the sealing drum 24 and, consequently, one complete revolution for each four full turns of the collecting drum. 419.

The cam groove 494 of the disc earn 4% is at constant radial distance from the axis of its supporting stub shaft 493 throughout the major portion of its angular extent but is provided with a rise portion 59% (FIGS. 3 and 4) of short angular extent and disposed at a greater radial distance from the axis of the stub shaft 498. So long as the follower roller 492 is within the part 519 of the cam groove 498 of lesser radius, the crank arm 49%) remains stationary, holding the jaw-operating disc earn 470 in that position in which bags are permitted to enter between the jaws 442 and 444. However, when the shifting earn 498 turns so as to dispose the follower roller 492 in the rise portion 508, the crank arm 4% is caused to turn clockwise as viewed in FIG. 3, far enough to tum the jaw actuating disc earn 47% to its alternative position, i.e., the position in which the collected group of bags is permitted to depart from the circumference of the drum are.

It will be understood from the above description that when a group or" four bags have been collected by the collecting drum 41h, the leading edge of one of the bags of the group will be disposed radially outward from the fingers 452 of the movable jaw 444 and that the leading edges of the other three bags will be disposed radially inward of the fingers 452. As a consequence, a stripper mechanism 52% (PEG. 3) is provided to snap the leading edges of the three bags outward past the fingers 452 to permit them to deviate from the circular orbit through which they were previously carried by the rotating drum 413. The stripper mechanism 524) is arranged within the collecting drum 41% and includes a support rod 522 secured at its ends to the heads 415 of the drum 410 and extending the full length of the drum therebetween. A pair of parallel levers 524, meet which is shown in PEG. 3, are pivoted upon the support rod 522, one adjacent each of the drum heads .15., A bar 526 interconnects the two levers 524, being rigidly secured thereto adjacent the outer ends of the levers. A plurality of stripper fingers 528 are carried by the bar 526 in positions to be projected through the opening 448 in the circumferential wall of the drum 416 when the levers 524 re pivoted in a counterclockwise direction as viewed in FIG. 3, from the position in which one of them is illustrated in that figure. Moreover, the stripper fingers 528 are so spaced apart and are so related to the fingers 452 of the movable jaw 444 that when the fingers 528 are thus projected through the opening 449 one stripper finger 52% passes between each two adjacent fingers 452 of the movable jaw 444 and thus positively snaps the entrapped bags radially outward beyond the fingers 452, releasing them to be advanced along the straight horizontal portions of the belts 426.

One end of the bar 526 projects beyond the support lever 524 at the corresponding end of the row of stripper fingers and is engaged by one end 53% of a torsion spring 532 that encircles the support rod 522. The other end 534 of the spring 532 engages an abutment pin 536 rigid with and projecting laterally from an operating lever 538 that is mounted for free rotary movement upon the support rod 552 alongside the proximate lever 524. Adjacent the operating lever 533 a stationary disc cam 54% is mounted, and its peripheral edge is engaged by a cam follower rolier 542, carried by the operating lever 538.

The entire stripper unit 543 consisting of the operating lever 533, and two parallel levers 524, the bar 526 that connects the two parallel levers 524, and the group of stripper fingers 528 is constantly urged toward the inner, in operative position illustrated in FIG. 3, by means of a coil spring 544 that is under tension between a pin 546 rigid with the operating lever 538 and a screw 548 carried by one of three stabolts 550 that rigidly interconnects the two heads 415 of the drum 410. Thus, the spring 544 holds the follower roller 542 against the periphery of the cam 540, but yields as rotation of the drum 410 causes the follower roller 542 to ascend the rise 551 of the cam 540.

The abutment pin 536 against which the end 534 of the spring 532 bears, projects laterally from the operating lever 538 and into a hole 552 in the adjacent stripper finger support lever 524. The hole 552 is larger than the cross-sectional area of the abutment pin 536 and consequently if outward radial movement of the stripper fingers 528 is interrupted when the stripper unit 543 is turned counterclockwise as viewed in FIG. 3 by the follower roller 542 ascending the cam rise 551, such rotary movement of the support levers 52.4 and stripper fingers 528 will terminate although the operating lever 538 will continue to swing counterclockwise, with the abutment pin 536 moving away from the edge of the hole 552 against the urge of the spring 532, until the cam follower roller 542 reaches the crest of the cam rise 551.

The cam 540 is stationary, being fixedly mounted within the drum 416 by means of a sleeve 560 (FIG. 3) to which the cam 540 is rigidly secured by a plurality of screws 562. The sleeve 56% extends through the adjacent drum head 415 and is rigidly secured to a plate 564, (FIG. 1) which is mounted upon and rigidly secured to the frame extension 432 as by a cap screw 566 or other suitable fastener. The associated drum head 415 rotates freely around the stationary sleeve 569 which may, therefore, serve as a bushing that provides the journal for the drum head, or, alternatively, suitable anti-friction bearings (not shown) may be interposed between the sleeve 566 and the associated drum head 415.

FIGS. 6-10, inclusive, illustrate the manner of operation of the bag gripping jaws 442 and 444 of the collecting drum 419 and of the stripper mechanism 520. As the first bag 13-1 of four successive bags approaches the collecting drum 410 on the belts 426, the cam follower roller 466 (FIG. 5) encounters the rise 476 of the cam groove 468 of the face cam 470,-pushing the roller 466 radially outward and causing the movable jaw 444 to swing to its open position as indicated in FIG. 5, thereby leaving a gap into which the leading end of the bag B-1 enters. Briefiy thereafter during the continued rotation of the drum 41d and continued advance of the bag B1, the cam follower roller 466 encounters the return slope or fall 477 of the cam groove 468, whereupon the movable jaw 444 is returned to its clamping position with a leading end of the bag B-l gripped between the jaws 442 and 444 as shown in FIG. 7.

When the drum 410 has turned some 10 or 15 beyond the FIG. 6 position the cam follower roller 542 on the operating lever 538 of the stripper mechanism 52%) encounters the rise 551 of the cam 540 and as the drum 41d continues to rotate the cam follower roller 542 is forced radially outward causing the unit 543 of the stripper mechanism 52% to swing radially outward about the support rod 522. Before the cam follower 542 reaches the crest of the rise 553, the outer ends of the stripper fingers 523 encounter the bag B-l so closely adjacent the leading end thereof that continued outward movement of the fingers 528 is arrested by the fingers 452 of the movable jaw 444 as shown in FIGURE 7. In view of the fact that the abutment pin 536 engages the adjacent stripper finger support lever 524 only within the relatively large hole 552, the actuating lever 53% is permitted to continue its outward movement until its cam follower 542 reaches and passes over the crest of the cam rise 551 Without corresponding outward movement of the stripper fingers 528, as is likewise shown in FIG. 7.

Consequently, as the drum 419 continues to rotate it carries with it the bag Bl so that the bag is wrapped upon the surface of the rotating collecting drum 410 and follows a circular orbit corresponding to the circumference of the drum.

This operation is repeated as the next succeeding bag B-2 approaches the drum 41% and is grasped by the jaws 442 and 444 so that the bag B-Z likewise is caused to wrap itself upon the outer surface of the bag B1 and both bags B1 and 13-2 follow the circular orbit in superimposed relationship upon the circumference of the drum 410. The operation is repeated again with the next following bag 3-3 as indicated in FIGS. 8 and 9. However, FIG. 9 shows the apparatus shortly after the fourth cycle of operation of the rotating collecting drum 414 has commenced.

Just before the beginning of the fourth cycle, the face cam 470 is rotated clockwise as viewed in FIG. from the position in which it is illustrated in that figure by the cooperative action of the cam follower roller 4-92 (FIG. 3) and the cam groove 508, as hereinabove escribed. Consequently, the leading end of the fourth bag B-dreaches the drum 410 and the movable jaw 44-4 before the latter is moved to its open position and will therefore be caused to overlie the fingers 452, i.e., will be disposed radially outward of the fingers 452 as shown in PEG. 9. Shortly thereafter the cam follower roller 542 (FIG. 3) encounters and is moved radially outward by the cam nise 551 and the stripper mechanism 526 is actuated thereby.

' At this time, however, the cam follower roller 466 (PEG.

5) will not have reached the return slope 477 of the cam groove 468 because of the advanced position then occupied by the face cam 470. Therefore, the fingers 452 (FIG. 3) of the movable jaw 444 will be withdrawn from the path of outward movement of the stripper fingers 528 so that as the cam follower 542 achieves the crest of the cam rise 551'the stripper fingers 528 will reach the outer limit of their movement as shown in FIG. 10 snap- I ping the leading ends of the bags B-l, B2, and B3 outward past the fingers 452 causing them to overlie the leading end of the bag B4. Thus, the entire group of bags Bl, B2, B3, andB-4 will be free to digress from the circular orbit theretofore traveled by the bags BIl, B2, and B-3 and all four bags will depart from the drum 41% along the straight, horizontal portions of the belts 4-26.

The group of four bags is advanced by the belts 426 onto an auxiliary senies of spaced parallel belts 58G (FIGS. 2 and 3) which are also trained around the roller 428. Since the roller 428 is rotated by means of the belts 426 the roller 428 likewise serves as a means for driving the belts 589. One of the belts 586 is disposed between each two adjacent belts 426 where they are trained around the roller 428. Each of the belts 580' is likewise trained around an idler roller 582, all of which are rotatably mounted on a shaft 584 which is mounted in the frame of the machine similarly to the shaft 430 of the roler 428. 7

The advancing group of four bags is held down on the auxiliary belts 580 by an overhead series of belts 586, each of which is trained around a pulley 588 carried by a bracket 590 adjustably mounted upon a transverse rod 592 and adapted to be clamped in adjusted position thereon as by a cap screw 594, as is clearly shown in FIG. 3. All of the belts 586 are trained around a driving roller 596 (FIGS.l and 2) which is driven from the gear 4-14 of the collecting drum 410 by means of rigidly interconnected gears 597 and 598, a driven gear 68% secured to a shaft 602, an idler gear 604, and a driven gear 6'95 (FIG. 1) rigid with the roller 596. The gears 597 and 593 are rotatable upon a stub shaft 606, and the idler gear 664 is rotatable upon a stub shaft 698, both stub shafts 6G6 and 608 being rigid with and projecting laterally from the frame extension 432, whereas the transverse rod 592, the shaft 602, and the shaft 610 of the driving roller 596 are carried by and extend between the two frame extensions 432 and 43 In addition to the gear 6%, the shaft 6il2 carries a plurality of spaced-apart discs or wheels 616, each of which is of such radius that its peripheral edge is disposed between two adjacent ones of the idler rollers 582 on which the belts 5 89* are trained, as best shown in FIG. 3. Consequent'ly, as a group four bags approaches the discharge end of the auxiliary belts 536, the group is corrugated in a series of alternate ridges and valleys which impart to the group of bags sufiicient longitudinal rigidity to hold the group of bags relatively straight as their leading ends advance off the belts 58th The hereinbefore mentioned discharge conveyor 28 (FIGS. 1 and 2) extends out from under the belts 536 and comprises a transversely flat, relatively wide belt 622 trained around a driving roller 624 rotatably mounted in the frame of the machine below the belts 580', and around an idler roller (not shown) journalled on and extending between frame extensions 628 and 631' respectively, at the discharge end of the machine 24 The driving roller 624 (FIG. 2) is driven intermittently and at quite slow speed by the hereinbefore mentioned idler gear 412 whose shaft 640 (FIGS. 2 and 4) is journalled in and extends through the frame extension 432 to receive on its outer end a bevel gear 642 (FIG. 4) which is enmeshed with a driven bevel gear 644 carried by a shaft (not shown) which is journalled in brackets 646 and 648 secured to and projecting outward from the outer face of the frame extension 432. This shaft carries a driving worm 650 enmeshed in driving relation with a worm wheel 652 which is carried by a shaft 654 journall'ed in and extending through the frame extensions 432 and 434-.

On the opposite side of the frame extension 432 from the worm wheel 652, the shaft 654 carries a disc 656 (FIG. 2) having in its peripheral edge a notch 65%; of approximately 15 angular extent. Also rigidly secured to the shaft 654- is a second disc 66%} of such size that throughout the major portion of its angular extent, the periphery of the disc 66% is of lesser radius than the bottom of the notch 658. However, at that segment of the second :disc 66% which is in alignment with the notch 658, the second disc 66% llS provided with gear teeth 662.

A stub shaft 664- journalled on the frame extension 432, carries a disc 666 in planar alignment with the disc 656 andhaving three arc-uate notches 668 therein, each of which has a curvature complementary to that of the periphery of the disc 656. Throughout the time that any portion of the periphery of the disc 656 except the notch 658 is adjacent the disc 666 the periphery of the former fits Within and slides relatively to one of the notches 668, thus holding the disc 666 from rotating. Secured to the disc 666 in coaxial relation therewith is a gear 676 whose teeth are adapted to be engaged by the teeth 662 of the disc 660 whenever the notch 658 of the disc 656 turns to its position closest to the disc 666. There being three notches 668 in the disc 666, it becomes apparent that the disc 666 and the gear 670 will be caused to turn /3 of a revolution each time the discs 656 and 65% experience one full turn.

An idler gear 672 is suitably journalled upon the frame extension 432 and is enmeshed with both the gear 679 and with a gear (not shown) rigid with the shaft 674 of the driving roller 624 of the discharge conveyor 28. Thus llt may be seen that the discharge conveyor 28 is actuated to move the upper run of tits belt 622 a short distance toward the discharge end of the machine 20 each time a predetermined number of groups of bags are discharged from the belts 580 and 536.

The stacking mechanism also includes a gate mechanism 68!) (FIGS. 1 and 2) whose function is to, intercept the successive groups of bags as they are discharged from the belts 580 and 586 onto the discharge belt 622. The

gate mechanism 680 comprises a plurality of horizontally spaced vertical rods 682 rigid with, and projecting downward from, a horizontal support bar 684- which is carried by a crank arm 636 and which projects laterally therefrom over the discharge belt 622. The crank arm 686 is rigid with a shaft 638 that is rotatably supported by an upward extension 6% of a box frame 692 that is slidable longitudinally of the discharge conveyor 23 between the inwardly extending flanges 694 of one of two channel members 696 which constitute the side frame members of the discharge conveyor 28. The box frame 692 is adapted to be releasably clamped in selected position of longitudinal adjustment upon the associated channel member 696 by means of two knobs 698 (one of which isshown in FIG. 1) each of which is threaded upon a stud (not shown) rigid with the box frame 692 and projecting laterally outward therefrom through a longitudinal slot 701 (FIG. 2) in the web of the channel member 696. Each of the two locking knobs 698 is knurled as indicated at 762 to facilitate manipulation thereof without necessitating the use of a wrench.

The shaft 688 which carries the crank arm 686 also carries a disc 784 (FIG. 2) whose circumference is covered by a strip 786 of suitable friction material.

The shaft 688 is adapted to be turned periodically so as to lift the rods 682 of the gate mechanism 68% each time a predetermined number'of groups of bags have been intercepted by the rods 682 and thus caused to drop in stacked relation upon the discharge conveyor belt 622. The gate lifting means cooperates with the disc 704 and comprises a shaft 710 (FIG. 2) journalled in the box frame 692 and extending transversely thereof. To the shaft 710 arm 712 is rigidly secured projecting radially therefrom. The outer end of the arm 712 is formed in an arc whose center lies in the axis of the shaft 714); Moreover, the arm 712 lies in planar ali r ment with the disc 794 and is of such length that when the shaft 710 is turned so that the arm 712 projects toward the disc 764 the outer, arcuate end of the arm makes frictional engagement with the outer surface of the friction strip 7 l6 and thus, as the shaft 710 continues to turn, imparts rotary movement to the shaft 688.

The means for turning the shaft 714 comprises a spiral gear 714 rigid therewith and enmeshed with a companion spiral gear 716- which is slidable upon and is connected by means of feather key (not shown) to a longitudinally extending shaft 718 which is journalled adjacent its ends in brackets 72!} secured to the inner face of the frame extension 639. The shaft 718 is likewise journalled in brackets 722 carried by the box frame 692 and slidable along the shaft 718 when the box frame 692 is shifted longitudinally of the discharge conveyor 28. The shaft 718 has a bevel gear 724 afiixed thereto which is in meshmachine from the discs 653 and 66%.

For each full turn of the shaft 654 and the discs 653 and 660, advancing the discharge conveyor belt 622 a short distance as hereinabove explained, the shaft 714 will likewise be turned through one complete revolution.

Therefore, during the period that the desired number of groups of bags are collecting behind the gate mechanism 630, the discharge conveyor belt 622 remains motionless ing engagement with a companion bevel gear 726 secured to the shaft 654 adjacent the opposite side of the and the gate mechanism 680- remains in bag intercepting position as illustrated in FIG. 2. However, the arm 712 is so related to the discs 658 and 666 that as said discs beginjto rotate the shaft 714 immediately after the desired number of groups of bags have been collected, the

belt 622 and thereby permit the pile of bags to advance until at least their leading edges have passed the rods 682. When the arm 712 passes out of engagement with the friction strip 766 of the disc 764 the rods 682 will gravitate back to their position illustrated in FIG. 2 and thus be conditioned to intercept the next group of bags to be discharged from the belts 586 and 586.

A pair of laterally-spaced, longitudinally extending belts 749 and 742 (FIGS. 1 and 2) are provided above the discharge conveyor 622 to provide lateral support for the stacks of bags as they accumulate behind the gate mechanism 689 and as they are advanced upon the conveyor belt 622 after the gate mechanism 680 has been actuated to release them. Each of the belts 740 and 742 is trained around two pulleys 744 and 746 (FIG. 2) which are disposed with their axes vertical and which are spaced apart longitudinally of the discharge conveyor 28. The pulley 744 of each belt 740, 742 is rotatable upon a vertical shaft 748 (FIG. 2) rigid with and extending downward from a block 759 that is carried by and is slidable along a transversely extending rod 752 (FIGS. 1 and 2) whose ends are rigidly secured to posts 754 (FIG. 1) upstanding from the channel-shaped conveyor side members 696. The parts are so arranged that the transverse rod 752 supports the two pulleys 744 just forward of the forwardmost position of the box frame 692 of the gate mechanism 689 as best shown in FIG. 2.

Each of the rear pulleys 746 of the two belts 746* and 74-2, respectively, is rigidly secured to a vertical shaft 766 (FIG. 2) whose upper end extends through the web or bight portion (not shown) of a U-shaped bracket 761 (FIGS. 1 and 2) and between the legs 762 thereof where it carries a bevel gear 764 rigidly secured thereto. Each of the two bevel gears 764 is enmeshed with a companion bevel gear 766 which is slidable axially upon a drive shaft 768 disposed above the conveyor belt 622 in horizontal alignment with the transverse rod 752. The drive shaft 768 is journalled in two posts 77%, each of which is rigid with, and rises from, one of the channel-shaped conveyor frame side members 696. The drive shaft 768 extends through and is free to rotate with respect to all four of the bracket legs 762. Moreover, these brackets 761 are free to slide axially of the drive shaft 768.

Thus it may be seen that the transverse spacing between the belts 746' and 742 is Variable by sliding the blocks 75% along the transverse rod 752 and by similarly sliding the bevel gears 766 and-the brackets v761 within which they are disposed axially along the drive'shaft When the belts 7453 and 742 have thus been adjusted to make the spacing between their inner runs substantially' correspond to the width of the bags to be produced, 'the blocks 754} should be anchored in their adjusted position upon the transverse rod 752. by set screws 772 which are provided for that purpose. The bevel gears 766 are likewise provided with set screws 774 which not only retain the bevel gears and their associated parts in selected position of adjustment axially along the drive shaft 763but they also affix the bevel gears 766 to the drive shaft 768 so as to be rotated thereby.

- The shaft 768 is driven by a chain 7-80 (FIGS. 1 and 2) trained around a sprocket 782, which is secured to the shaft 768 and around a sprocket 784 (FIG. 4) rotat able upon a stub shaft 786 secured to and projecting laterally outward from-the outer face of the frame extension 432. The stub shaft 786 also carries a driven ;gear 787 (FIG. 1) which is enmeshed with a gear 788 which is-rigid with an end of the shaft 674 of the roller 624 (FIG. 2) whereby the discharge conveyor belt 622 the same speed as the upper run of the horizontal discharge conveyor belt 622.

As each successive group of bags emerge from between the belts 580 and 586 (-FIG. 2) they drop onto the horizontal discharge conveyor belt 622 between the inner runs of the two vertical belts 740 and 742. Thus the belts 740 and 742 provide lateral guides for the bags as they accumulate in stacked relation upon the belt 622 behind the gate mechanism 680. In this manner each stack of accumulated bags is retained in neat, orderly arrangement, which arrangement is retained when the gate mechanism 680 releases each accumulated stack inasmuch as the vertical belts 740 and 742 are advanced simultaneously and coextensively with advance of the horizontal belt 622.

As the stacks of bags are thus advanced on the discharge conveyor belt 622 the successive stacks will usually be in overlapping relation inasmuch as under most circumstances the length of the bags being produced will be greater than the distance that the belts 622, 740 and 742 are advanced during each actuation thereof. Nevertheless the stacks will be clearly defined and can readily be removed by an attendant from the discharge conveyor belt 622 without permitting any of the bags of any one pile to become displaced from that pile and, therefore, without disturbing the count of bags within each pile.

While a particular embodiment of the present invention has been shown and described, it will be understood that the apparatus is capable of modification and variation without departing from the principles of the invention and that the scope of the invention should be limited only by the scope and proper interpretation of the claims appended hereto.

The invention having thus been described, that which is believed to be new and desired to be protected by Letters Patent is:

1. In apparatus for handling bags formed of plastic sheet material, a rotatably mounted collecting drum, a stationary jaw rigid with and extending longitudinally of the drum adjacent the periphery thereof, a movable jaw mounted on the drum parallel to the stationary jaw for movement to and from gripping relation therewith, means for advancing bags successively along a path a portion of which is contiguous to a portion of the periphery of the drum, means for rotating the drum in timed relation with said bag advancing means to repeatedly place said jaws at the area of contiguity of the path and drum as a bag reaches said area of contiguity, a cam mounted in cooperative relation with said drum, a cam follower engaged with said cam and operatively connected with said movable jaw for maving said movable jaw away from said stationary jaw prior to each arrival of the jaws at said area of contiguity to receive the leading edge of each successive bag between the jaws and for returning the movable jaw to gripping relation with the stationary jaw prior to departure of the jaws from said area of contiguity to attach groups of the bags to the drum, and means operative after a predetermined number of bags have been attached to the drum for rotating said cam to defer movement of themovable jaw away from the stationary jaw until after arrival of the jaws at said area of contiguity a'nd'to defer return of the movable jaw to gripping relation until the jaws have departed from said area of contiguity to release bags collected thereby for resumed movement along said path.

2. In apparatus for handling bags formed of plastic sheet material, a rotatably mounted collecting drum, a stationary jaw rigid with and extending longitudinally of the drum adjacent the periphery thereof, a movable jaw mounted on the drum parallel to the stationary jaw for 12 movement to and from gripping relation therewith, belt means for advancing bags successively along a path ap proaching the drum, said belt contacting said drum over a portion of its peripheral surface, means for rotating the drum in timed relation with said belt means to repeatedly place said jaws in a position adjacent said belt means as bags reach the drum, shiftable means mounted in cooperative relation with said drum for moving said movable jaw away from said stationary jaw prior to each arrival of the jaws at said position to receive the leading edge of each successive bag between the jaws and for returning the movable jaw to gripping relation with the stationary jaw prior to departure of the jaws from said position to collect a group of the bags on the drum, means operative after a predetermined number of bags have been collected on the drum for shifting the jaw moving means to defer movement of the movable jaw away from the stationary jaw until after arrival of the jaws at said position and to defer return of the movable jaw to gripping relation until the jaws have passed said position to release the group of bags previously collected thereby, and stripper means carried by the drum and operative after the jaws have passed said position immediately prior to a deferred return of the movable jaw to gripping relation to strip from between the jaws bags previously gripped thereby for continued advancement by said belt means.

3. Apparatus for stacking bags formed of plastic sheet material comprising a rotatably mounted collecting drum,

a stationary jaw rigid with and extending longitudinally of the drum adjacent the periphery thereof, a movable jaw mounted on the drum parallel to the stationary jaw for movement to and from gripping relation therewith, means for advancing bags successively along a path a portion of which is contiguous to a portion of the periphery of the drum, means for rotating the drum in timed relation with said bag advancing means to repeatedly place said jaws at the area of contiguity of the path and drum as a bag reaches said area of contiguity, shiftable means mounted in cooperative relation with said drum for moving said movable jaw away from said stationary jaw prior to each arrival of the jaws at said area of contiguity to receive the leading edge of each successive bag between the jaws and for returning the movable jaw to gripping relation with the stationary jaw prior to departure of the jaws from said area of contiguity to attachsgroups of the bags to the drum, means operative after a predetermined number of bags have been attached to the drum for shifting said jaw moving means to defer return of the movable jaw to gripping relation until the jaws have departed from said area of contiguity to release bags collected thereby for return of the collected bags to said advancing means and resumed movement of the collected bags along the path in a group, means for imparting rigidity to each group of bags as they are advancedalong said path, a discharge conveyor operably mounted in position below said advancing means to receive successive groups of bags from said advancing means, and means for advancing said discharge conveyor at a rate of travel less than that of said advancing means.

References Cited in the file'of this patent UNITED STATES PATENTS 374,930 Brooks Dec. 20, 1887 1,068,597 Main July 29, 1913 1,545,916 Maxson July 14, 1925 2,278,188 Bamford et al. Mar. 31, 1942 2,708,863 Payne May 24, 1955 

1. IN APPARATUS FOR HANDLING BAGS FORMED OF PLASTIC SHEET MATERIAL, A ROTATABLY MOUNTED COLLECTING DRUM, A STATIONARY JAW RIGID WITH AND EXTENDING LONGITUDINALLY OF THE DRUM ADJACENT THE PERIPHERY THEREOF, A MOVABLE JAW MOUNTED ON THE DRUM PARALELL TO THE STATIONARY JAW FOR MOVEMENT TO AND FROM GRIPPING RELATION THEREWITH MEANS FOR ADVANCING BAGS SUCCESSIVELY ALONG A PATH A PORTION OF WHICH IS CONTIGUOUS TO A PORTION OF THE PERIPHERY OF THE DRUM, MEANS FOR ROTATING THE DRUM IN TIMED RELATION WITH SAID BAG ADVANCING MEANS TO REPEATEDLY PLACE SAID JAWS AT THE AREA OF CONTIGUITY OF THE PATH AND DRUM AS A BAG REACHES SAID AREA OF CONTIGUITY, A CAM MOUNTED IN COOPERATIVE RELATION WITH SAID DRUM, A CAM FOLLOWER ENGAGED WITH SAID CAM AND OPERATIVELY CONNECTED WITH SAID MOVABLE JAW FOR MAVING SAID MOVABLE JAW AWAY FROM SAID STATIONARY JAW PRIOR TO EACH ARRIVAL OF THE JAWS AT SAID AREA OF CONTIGUITY TO RECEIVE THE LEAD- 